Archaeopteryx

When it was first discovered in Germany in 1861, Archaeopteryx was hailed as the missing link between birds and dinosaurs and proof for the theory of evolution.…Read More »

This raven-sized animal lived about 150 million years ago and had feathers identical to that of modern flying birds. But Archaeopteryx also had sharp teeth, a long bony tail and clawed fingers. Less «

2 of 20

Beipiaosaurus

Credit: Reconstruction by Zhao Chuang and Xing Lida.

At 7 feet long and 3 feet tall, Beipiaosaurus is one of the largest known feathered theropods the group of swift upright dinosaurs from birds are thought…Read More »

to be descended. For a long time, scientists didn't know how to classify Beipiaosaurus because it shared characteristics more commonly found among plant eating dinosaurs. It lived about 125 million years ago and had a toothless beak, cheek teeth that it used to chew plants and the beginnings of a bulging pot belly. But theropods are the only group of dinosaurs so far known to have feathers, and many scientists take Beipiaosaurus' feathers as evidence for it being a theropod. Less «

3 of 20

Caudipteryx

Credit: Matt Martyniuk

Caudipteryx was a peacock-sized theropod that lived about 125 million years ago. And just like a peacock, it had long plumed tail-feathers that it may…Read More »

have fanned out for display. Caudipteryx also had down feathers covering most of its body that helped to keep it warm. Less «

4 of 20

Coelophysis

Coelophysis was a small, compact dinosaur that lived about 210 million years ago. It was a quick and agile hunter that had hollow bones and a hole-ridden…Read More »

skull, which helped to reduce its weight and increase its speed. Some fossils have been found with other small Coelophysis bones inside, and at first, it was thought that Coelophysis might have given birth to live young. It is now believed, however, that it was probably a cannibal that occasionally devoured its own young. Less «

5 of 20

Compsognathus

Credit: Daniel Bensen

Compsognathus is one of the smallest dinosaurs ever discovered. It lived about 150 million years ago and was possibly an early relative of Archaeopteryx.…Read More »

Compsognathus had long legs, hollow bones and a long rigid tail that it used to balance itself while chasing down quick-footed prey. Less «

6 of 20

Confuciusornis

Credit: Eduard Solà Vázquez

About the size of a crow, Confuciusornis is the earliest known bird to have a true beak. It lived about 10 to 15 million years after Archaeopteryx, but…Read More »

like its early ancestor, it still had clawed fingers. Males were typically larger than females and sported long, narrow tail feathers that they may have used to attract mates. Some scientists question whether Confuciusornis was a direct ancestor of modern birds. They propose instead that it was a cousin that early on went its own separate way. Less «

7 of 20

Dilong

This early cousin of Tyrannosaurus rex lived about 130 million years ago and was covered in hairlike protofeathers, which are precursors to the feathers…Read More »

of modern birds. It is named after the mythical Chinese Emperor dragon, Dilong, and from the fact that it was "paradoxically," small and feathered. The feathers were probably used for warmth, and scientists suspect that juvenile T-rexes might also have had feathers, and that the feathers were shed as the animal matured. Less «

8 of 20

Dromaeosaurus

Dromaeosaurus was a small, fast-moving predator that lived about 170 million years ago. It was about 6 feet long and was a dromaeosaurid, the family of…Read More »

dinosaurs that also includes Velociraptor. It had excellent vision, thanks to its large eyes, and scientists think that it also had a strong sense of smell and good hearing. Dromaeosaurus teeth have been found among the fossils of much larger animals, leading some scientists to suspect that it may have hunted in packs. It is also possible that Dromaeosaurus was a scavenger. Less «

9 of 20

Falcarius

Credit: Gaston Design, Inc.

Scientists have long suspected that the lumbering plant-eating dinosaurs evolved from small fleet-footed predators, but no fossil had ever been found to…Read More »

support this theory. That is why many scientists were excited when Falcarius was discovered earlier this year, because it shared traits common to both groups. Falcarius lived about 125 million years ago and had unwieldy sickle-shaped claws, but short squat legs that would not have been very useful for chasing down prey. It also had the beginnings of a large pot-belly and leaf-shredding teeth. Less «

10 of 20

Longisquama

Credit: Nobu Tamura email:nobu.tamura@yahoo.com

This tiny animal is one of the reasons why the evolutionary link between birds and dinosaurs is still an issue of debate. It is the oldest animal ever…Read More »

known to have what appears to be feathers, but it was not a dinosaur. Rather, Longisquama was a small reptile, a lizard-sized creature that lived in Central Asia 220 million years ago. It walked on four legs and had feather-like appendages protruding from its spine, which it may have used to glide between trees. Less «

Mei long

Mei long was a small duck-sized dinosaur that lived about 130 million years ago. In Chinese, its name means "soundly sleeping dragon," a reference to the…Read More »

posture in which it was discovered: curled up with its head tucked under a forelimb. This posture is identical to that used by modern birds while dozing. Scientists think that birds sleep this way to keep warm, and the discovery of Mei long supports the theory that some dinosaurs were warm-blooded like modern birds. Less «

Microraptor

Like Archaeopteryx, Microraptor was about the size of a crow and had teeth, claws and feathers on all four limbs that it may have used to glide between…Read More »

trees. However, it is more closely related to dinosaurs than to birds, and many scientists believe that this 124 million-year-old dinosaur may be the long-sought missing link between the two groups. Less «

13 of 20

Ornithomimus

Credit: Art by Todd Marshall, courtesy of Project Exploration

Ornithomimus, whose name means "bird-mimic," was an ostrich-like dinosaur that lived approximately 70 million years ago. It was about 10-15 feet long —…Read More »

most of which was taken up by its neck and tail — and had a horny beak, a small head and hollow bones. It was fast and agile, and may have been able to run at speeds of up to 70 mph as fast as a cheetah. Less «

Oviraptor

Oviraptor was a small bird-like animal that lived about 80 million years ago. It had long slender legs, squat, strong arms, and a short toothless beak.…Read More »

It also had a small horn-like crest that it probably used for mating displays. Its name in Latin means "egg thief," because the first Oviraptor fossil ever discovered was found near what was thought to be a Protoceratop's nest. However, closer analysis later revealed that the nest contained Oviraptor eggs. This has lead to Oviraptor's image-makeover in recent years from that of an egg snatcher to a nurturing parent. Less «

15 of 20

Rahonavis

Credit: Nobu Tamura email:nobu.tamura@yahoo.com

This raven-sized animal belonged to the same group of dinosaurs as Velociraptor, but it had many bird-like features. Rahonavis lived about 80 million years…Read More »

ago and had a retractable "sickle-claw" on the middle toe of each foot. It had feathered wings like a bird but a long bony tail like Archaeopteryx. Less «

16 of 20

Sinornis santensis

Credit: Sereno and Chenggang, Science, 1992

About the size of a sparrow, Sinornis santensis lived about 135 million years ago and was probably an excellent flier that was capable of sustained flight.…Read More »

Itâ€™s slender legs and sharp claws were ill-equipped for walking but it was able to perch and to skitter up and down trees. It was more bird-like than its ancestor Archaeopteryx, but it still had teeth and a short snout instead of a true beak. Less «

17 of 20

Sinornithosaurus

Credit: Robert DePalma.

Sinornithosaurus was the fifth and most bird-like feathered dinosaur species ever to be discovered. It lived about 125 million years ago and was a dromaeosaurid.…Read More »

Its discovery strongly suggests that other dromaeosaurids may have also had feathers. Some scientists believe that its discovery is proof that feathers first developed in quick-footed, ground-dwelling dinosaurs, instead of those that lived in trees. Less «

Sinosauropteryx

Like Micropteryx, Sinosauropteryx was more closely related to dinosaurs than to birds, and yet it clearly had feathers. It was about 3 feet long and lived…Read More »

in China about 125 million years ago. It had long legs, short arms, a long bony tail and it probably ate insects and small animals. Less «

19 of 20

Troodon

Credit: Todd Marshall

Troodon had one of the largest brain-to-body size ratios of any known dinosaur and it is believed to have been one of the most intelligent dinosaurs that…Read More »

ever lived. Its large, slightly forward facing eyes suggest that it was a nocturnal creature with excellent depth perception and it had long arms that it could fold back like a bird. It lived about 70 million years ago. Less «

20 of 20

Velociraptor

Credit: Todd Marshall

Velociraptor is one of the most bird-like dinosaurs ever discovered. It was small and fast, and the sickle-shaped claw on the second toe of each foot made…Read More »

it a formidable predator. A special bone in its wrist allowed it to swivel its wrist sideways in a flapping motion and to fold its arm against its body like a bird. This motion allowed it to snap its arms forward to grab fleeing prey and is an important part of the flight stroke in modern birds. Less «

Science Newsletter: Subscribe

Follow Us

More from LiveScience

Author Bio

Live Science Staff

For the science geek in everyone, Live Science offers a fascinating window into the natural and technological world, delivering comprehensive and compelling news and analysis on everything from dinosaur discoveries, archaeological finds and amazing animals to health, innovation and wearable technology. We aim to empower and inspire our readers with the tools needed to understand the world and appreciate its everyday awe.